I used to use those 35mm film containers for sending scorps although for the past couple of years i've been using small 1,5ml geocaching containers and 3,5ml paint pots for sending younger instars with excellent success. You can stand on those small containers without breaking or squashing them so you don't have to worry to much about a package being dropped breaking the containers within. For the small 1,5ml containers i just use a pencil to press a hole in a 45mm thick sheet of polystyrene and then press the geocaching container into the hole. It holds it snug, protects it, cuts down on the need for packing around the containers, also cuts down on the size of the package thereby decreasing shipping costs and just makes it simple and easy to ship small scorps. You just cut the polystyrene sheet to the inside measurement of your shipping box, minus 2 inches. This gives you one inch all around the polystyrene for you to add crumbled newspaper (Callum is right, newspaper is totally sufficient for absorbing general shakes, blows, drops, shakes etc), embed the packed scorps into the polystyrene, place another sheet on top, tape it and place it in the shipping box and fill the gap around it with newspaper...viola...The 3,5ml paint pots are done the same way although i use a drill to cut holes in the polystyrene sheet...I also use a few other sized containers for the larger scorps...I find all these containers on Ebay. All cost of containers/polystyrene sheeting is of course passed over to the buyer.
Despite their small size i can still press a wad of kitchen paper into the bottom of the containers, line them with kitchen roll (i place a small piece in and use a inverted paint brush to press it around the inside edge of the container) and for there still to be room for a small wad on top before sealing them. I add a drop (and only a drop) of water if necessary. If the package is expected only to be in transit for 2 or 3 days i don't even prick an air hole in the containers (allows the buyer to re-use them) although i will for longer transit times (i don't know if it's necessary though!).
I've yet to experience any DOA's.
Hm, for some reason i can't upload a pic of the containers to show you what i'm talking about but if you search for the terms i've used on Ebay you'll see what i mean.